A modular vehicle system may include an engine unit for propulsion and an implement unit. If an operator is manning or supervising a modular vehicle, the status of the implement may be observed visually, aurally or through gauges on an instrument panel. However, if an operator is not manning a modular vehicle or if the operator is impaired or distracted, there is a need provide technology that is a proxy for the observations, reactions, and control of the operator. Thus, there is a need for a modular vehicle system having an engine unit and a mower unit for communication therewith that supports unmanned operation or assistance to manned operation.